Bessel beam

About: Bessel beam is a research topic. Over the lifetime, 1946 publications have been published within this topic receiving 42264 citations.

Multiple input/output waveguides light-induced by a single Bessel beam for all-optical interconnects.

Abstract: We numerically study photo-induced waveguides using a single Bessel beam in a photorefractive (PR) medium. Under self-focusing nonlinearity, we demonstrate the possibility for creating complex waveguiding structures with multiple input/output channels. The truncation of the incoming Bessel beam, the nonlinearity of the PR medium, the light intensity, and the order and the size of the Bessel beam are the key parameters for achieving different configurations with high guiding efficiencies. As such, not only classical X or Y couplers but also more complex structures can be generated with up to 7 identified inputs/outputs. These results provide large opportunities for all-optical interconnects.

Measuring solid surface velocity and detection of particle movement by laser Bessel beams

Abstract: The details of a technique to measure solid surface velocity and detect particle movement are presented. This technique is based on the measurements of the frequency change of scattered light of particles crossing the fringes of a nearly Bessel beam formed by an axicon. Experimental results are presented and confirm the theoretical analysis and numerical simulations. Measurements of the movement of wires through the fringes were also performed.

Manipulating neutral particles in Bessel beams: From rings, through fixed helices, to three-dimensional traps

Abstract: The motion of neutral, polarizable atoms (also called neutral particles in this work) in the field of the Bessel beam is considered. It is shown in the numerical way that the Bessel rings, i.e., the regions of high energy concentration, can trap particles of positive polarizability (atoms in red-detuned beams). This trapping occurs only in the plane perpendicular to the wave propagation, and the motion along the beam is unrestricted. When the beam is superposed with the plane wave of the same frequency propagating in the same direction, the particles are guided along helices, fixed in space. The shape of these helices depends on the parameters characterizing the electromagnetic fields but not on the initial state of guided particles. Depending on the vorticity of the Bessel beam, these helices can be made left- or right-handed. In the special case of zero vorticity, the helices are degenerated to the true, three-dimensional rings, which can serve as three-dimensional traps. The emerging structure of potential valleys can be applied to parallel guidance or capture several independent atoms, each in its own trap.

Space-Fractional Bessel Beams with Self-Healing and Diffraction-Free Propagation Characteristics

Abstract: In the recent years, fractional-dimensional approach has gained the attention of researchers due to its applications in modeling complex structures. In this paper, we introduce a unique non-diffracting space-fractional Bessel beam using this approach. It encompasses the limiting cases of both the ordinary integer Bessel beam and the fractional Bessel beam. Contrary to the ordinary Bessel beam, the space-fractional Bessel beam can have an arbitrary noninteger dimension that is less than or equal to three. This beam preserves the non-diffractive nature of Bessel beam and other structured light beams, and is also self-healing in nature. The propagation features of this new class of Bessel beams are discussed in comparison with ordinary Bessel beams. Beams of these types have evident advantages in the near-field applications such as optical trapping and manipulation.

Optical shaping of surface metal microstructures via nondiffracting beam controlled atomic deposition

Abstract: The first experimental realization of the non-diffracting Bessel beam technique for micro-structuring of thin rubidium metallic films on the sapphire surface is reported. Rubidium atoms were deposited onto the cool sapphire windows from the heated central region of the evacuated cell under simultaneous illumination by a Bessel beam at 532 nm wavelength and 4.5 W/cm2 intensity. The approach of the optically controlled atomic deposition is based on the strong non-thermal photo-desorption of atoms from illuminated areas of dielectric surface diminishing the surface density of adsorbed atoms below the threshold of nucleation process, while in the dark areas concentration of adsorbed atoms exceeds the critical value and a metal film starts to grow. As a result, the annular Bessel beam optical pattern with 40 μm periodicity was reproduced with high contrast in the Rb deposits, thus creating the annularly micro-structured metal film on the sapphire surface. The diffraction efficiency of the metal grating with the estimated thickness of ∼40 nm was measured to be about 1.8%.